Somali pirates freed a North Korean chemical tanker and its 28 crew yesterday after the owners delivered a ransom, said the European Union Naval Force.
The MV Theresa VIII was hijacked last November, north-west of the island nation of the Seychelles.
The vessel had not asked for assistance but warships were monitoring the situation, said Cmdr John Harbour. He could not provide details on the ransom.
Also yesterday, the EU Naval Force said it intercepted two pirate groups. The two groups, each consisting of a mothership and two skiffs, were tracked by maritime patrol aircraft after commercial ships reported attempted attacks.
Seventeen pirates in total had been detained, Harbour said. One of the attacks took place nearly 1,600km from the Somali coast and the other one was northwest of the Seychelles.
The London-based International Maritime Bureau says Somali pirates captured 47 vessels last year and launched 217 attacks. More than 100 crew are still being held.
Pirates typically use larger ships to tow their small, fast speedboats out to sea. The motherships also carry extra food, water and fuel, allowing the pirates to extend their range away from the Gulf of Aden, which is heavily patrolled by a coalition of international navies.
Experts say piracy will continue to be a problem until an effective government is established on Somalia's lawless shores.